Adjustable sheet feeding means for fluid duplicating machines



April 6, 1954 c. A. BERGMAN 2,674,183

ADJUSTABLE SHEET FEEDING MEANS FOR FLUID DUPLICATING MACHINES Filed March 27, 1951 3 Sheets-Sheet l Inventor.- Car! ,4. Ber- 72700 flctorneys C. A. BERGMAN April 6, 1954 674,183 ADJUSTABLE SHEET FEEDING MEANS FOR FLUID DUPLICATING MACHINES 3 Sheets-Sheet 2 Filed March 27, 1951 fave/260w far! 14 fiery/nary by E 15.1mm

April 6, 1954 c. A. BERGMAN 2,674,183

ADJUSTA'BLE'. SHEET FEEDING MEANS FOR FLUID DUPLICATING MACHINES Filed March 27, 1951 s Sheets-Sheet s [mm/Ital":

Car! 14. Bergman y MEEQSW duo/ways Patented Apr. 6, 1954 UNITED STATES NT OFFICE ADJUSTABLE SHEET FEEDING MEANS FOR FLUID DUPLICATIN G MACHINES Application March 27, 1951, Serial N0. 217,749

3 Claims. (Cl. 101-1325) My present invention relates to new and improved apparatus for operating fluid duplicating machines of the type in which a master copy is secured to a drum or platen and clear sheets are fed to it by a pair of combined feeding, positioning and moistening rolls. As is well known to those skilled in the art, it is necessary that the clear sheet register perfectly with the master copy. In the operation of one type of such machines, for instance, that shown in Storck Reissue Patent No. 19,951 both the drum and the pair of positioning, feeding and moistening rolls (conveniently known as the feed rolls or the moistening rolls)- are stationary momentarily, while the clear sheet is pushed into the bite of the rolls, and therefore are started and stopped simultaneously. When such a machine is run at high speed, the weight and inertia of the parts which must be stopped and started suddenly puts a heavy strain on the moving parts. In another type of machine the rotation of the drum is continuous while the operation of the moistening rolls is intermittent. Such machines have been made with segmental gears and similar devices to effect the stopping and starting of the feed rolls while the drum is in continuous motion.

The machine embodying the present invention relates to the latter class of machines and the particular object of the invention is to provide mechanism which will rotate the drum continuously while operating the feed rolls intermittently, to permit the clear sheet to be positioned by contact with the bite of moistening rolls. Another object of the invention is to provide mechanism which will give smooth operation with relatively slow and easy acceleration and deceleration and thus allow operation at high speeds without excessive wear and tear on the parts.

In the drawings:

Fig. 1 is a top plan view of the machine embodying my invention, certain of the parts being broken away for clearness of illustration;

Fig. 2 is a section on line 2--2, Fig. 1, certain parts also being broken away;

Figs. 3, 4, 5 and 6 show successive positions of the linkage connecting the driving gear and the drum; and

Fig. 7 is a diagram illustrating the lay-out of the cam.

Referring now to the drawings, at H is shown the drum, at l2 the pressure roll, at. l3 and It a pair of rolls which combine the functions of positioning, feeding and moistening and at l5 the wick which supplies moisture to the surface of the moistening r011 M. The master copy is shown at 2B and one clear sheet at 2|, a second clear sheet being indicated in dotted line at 22. This sheet is shown bent upwardly or buckled, i. e. in the position which it occupies when the front edge is positioned by the bite of the feed rolls. Automatic feeding mechanism of the kind customarily employed on machines of this kind may be used, but it is not shown as it forms no part of the present invention.

The machine is provided with the usual frame 30 in which is mounted a drum shaft 3! on the outer end of which is a crank handle 32. The machine as shown is hand operated by means of the hand crank 32, but it will be understood that it may also be operated by power in the well known manner, if desired. The drum If is mounted on the shaft BI and is fast thereto. The shaft 3| also carries a driving gear 33 which can revolve freely on it. On the inside of the frame of the machine is located a fixed plate 34, having a cam groove 35, which in the form shown in the drawings is a track cam in the face toward the end of the drum. This cam is mounted with its center in line with the axis of rotation of the drum shaft 3| and is mounted on the inside of the frame 38 of the machine. The plate 34 is provided with slots 31 through which pass studs 38. The slots and studs permit the plate 34 to be rotated slightly about the axis of the drum shaft for a purpose to be described hereafter. On the outside of the machine is a thumb nut 40 on a screw stud M which passes through a slot 39 in the frame 313. By loosening the thumb nut 40 the cam plate 3 5 can be adjusted as required and thereafter fastened in position by tightening the thumb nut '38. For convenience, I provide a scale 45 on the upstanding portion of the frame of the machine to indicate the different positions of ad- J'ustment.

A stud 41 is fixed to one of the spokes 46 of the drum of the machine and extends between the spokes 48 of the gear 33. On the outer end of this.

stud is pivotally mounted one end of a link 5!),

55!, but this exact location is not essential, the

essential thing being that the cam follower 55 be placed or connected to the links in such manner that it will vary the angle between the two-links 5t and 52 during the cycle of the machine, This cam follower 55 runs in the cam track 35 of plate 34. The gear 33 meshes with the pinion 60 which, in turn, meshes with gear 6! on the end of the moistening roll M. It will, therefore, be seen that rotation of the main drum gear 33 rotates the moistening roll M in the same direction as the drum.

Referring now to Figs. 3, 4, 5, 6 and. 7 and particularly to Fig. 7 where the lay-out of the cam is shown, it will be seen that from the radial line A moving clockwise to about the radial line B, the distance of the cam .path from the center of rotation increases substantially uniformly. From radial line B to radial line there is a connecting portion. From radial line C to radial line D the curve is part of the circumference of a circle drawn about stud 53 as the center when it is in the position which it occupies when the cam follower 55 reaches radial line Ci. e. when, as will be explained, the stud 53 is stationary. This curve is drawn with a radius E equal to the length of the link 52 between centers. From radial line D to radial line A there is another connecting portion of the curve. In actual practice the curve between radial lines B and C is plotted to give a cycloidal deceleration while the curve between radial lines D and A is plotted to give cycloidal acceleration to gear 33.

The operation of the machine is as follows:

Starting with radial A-i. c. with the parts in the position shown in Fig. 3, and moving clockwise, the cam roll 55 moves outwardly away from the center, preferably at a substantially uniform rate, passing through the position shown in Fig. 4 until it reaches radial line B as shown in Fig. 7. Since the drum which is fixed on the main shaft rotates continuously, the drum gear also rotates, being pulled around by the linkage 56, 52 connected at its ends to the studs 47 and 53 on the drum and driving gear, respectively.

' There is, however, a'slight gain of the driving gear with respect to the drum owing to the increasing radius of the cam track and the consequent bending of the linkage, as shown in Figs. 3, 4 and 5. The relative angular displacement is indicated by the arrows marked on the drum and the gear and shows the amount of this gain. This gain of the driving gear over the drum is offset by the lag which takes place when the cam roll passes through the circumferential portion of the cam between radial line C and radial line D. In Fig. 6 the solid lines show the positions of the members when the cam roll is at radial line C and the positions when the cam roll is at radial line D are shown in dotted line.

The drum gear 33, the pinion 6!] and the gear on the moistening roll Bl are designed so that the drum has a surface speed slightly in excess of the surface speed of the moistening and feeding rolls and consequently the drum pulls slight- 1y on the clear sheet. This tends to hold it fiat on the drum and prevents wrinkling. It also gives a slight rubbing action of the clear sheet on the surface of the moistening roll and improves the wetting, When the cam roll 55 reaches radial line C and moves to radial line D, the gear 33 stands still, since at this time the cam roll is merely swinging the link 52 about the stationary stud 53 as a center as shown in Fig. 6 and, therefore, the drum is not able to pull the gear after it. Therefore, durin this time the pair of feeding, moistening and positioning rolls i3 and M which are driven by gears 33 and 60 are stationary and this permits the paper to be fed against the bite of the rolls while they stand still.

It will thus be seen that the mechanism embodying my invention permits the drum to rotate continuously while the gearing and feed rolls are stopped and started as required. By giving the portions of cam between radial lines B, C and D, A, respectively, the curves described, the parts can be given a smooth easy motion so that the feed rolls and connected mechanism are not started and stopped with a jerk and the wear and noise of operation of the machine is reduced to a minimum and the machine can run at high speed.

The ca-m plate 34, with its cam groove 35, being angularly adjustable provides a convenient means of adjusting the registration of the clear sheet with respect to the master copy since the position of the cam determines the angular position of the drum at which the feed rolls will start. Moving the cam plate 34 clockwise moves the printing toward the top of the clear sheet, while moving the cam plate counterclockwise lowers the printing on the clear sheet.

I claim:

1. In a fluid duplicating machine having a frame, a continuously rotating drum fixed on a shaft mounted in said frame and a pair of intermittently rotating feed rolls driven by the drum, the driving means including a stationary adjustable cam adjacent the end of the drum with the center of the cam in line with the axis of rotation of said shaft, said cam having a continuous cam surface about its center, a drum gear rotatable on said shaft concentric to said drum, gearing connecting the drum gear with said feed rolls, linkage comprising a pair of links pivotally connected to each other at their adjacent ends, one of said links being pivotally connected to the drum gear and the other of said links being pivotally connected to the drum, and a cam follower mounted on the linkage and engaging said cam to vary the angle between the two links, said cam being rotatable about its center to locate said cam surface in different positions of adjustment with respect to the frame.

2. In a fluid duplicating machine having a frame, a continuously rotating drum fixed on a shaft mounted in said frame and a pair of intermittently rotating feed rolls driven by the drum, the driving means including a stationary adjustable cam adjacent the end of the drum with the center of the cam in line with the axis of rotation of said shaft, said cam having a continuous cam surface about its center, a drum gear rotatable on said shaft concentric to said drum, gearing connecting the drum gear with said feed rolls, linkage comprising a pair of links pivotally connected to each other at their adjacent ends, one of said links being pivotally connected to the drum gear and the other of said links being pivotally connected to the drum, and a cam follower mounted on the linkage at the pivotal point of the pair of links and engaging said cam to vary the angle between the two links, said cam surface having a portion which causes said drum gear to remain stationary as the cam follower passes over it during the rotation of the drum, said portion being a portion of a circle, the center of which is the pivotal connection of the link on the drum gear and the radius of which is the distance between the pivot centers of that link, said cam being rotatable about its center to locate said cam surface portionin different positions of adjustment with respect to the frame.

3. In a fluid duplicating machine having a frame, a continuously rotating drum fixed on a shaft mounted in said frame and a pair of intermittently rotating feed rolls driven by the drum, the driving means including a stationary cam adjustably secured to the frame adjacent the end of the drum with the center of the cam in line with the axis of rotation of said shaft, said cam having a continuous cam surface about its center,,a drum gear rotatable on said shaft concentric, to said drum, gearing connecting the drum gear with said feed rolls, linkage comprising a pair of links pivotally connected to each other at their adjacent ends, one of said links being pivotally connected to the drum gear and the other of said links being pivotally connected to the drum, and a cam follower mounted on the linkage at the pivotal point of the pair of links, and engaging said cam to vary the angle between the two links, said cam surface having a portion which causes said drum gear to remain stationary as the cam follower passes over it dur- 2o ing the rotation of the drum, said portion being a portion of a circle, the center of which is the pivotal connection of the links on the drum gear and the radius of which is the distance between the pivot centers of that link, said cam surface having a second portion of progressively increasing the distance from the center to the cam, there being connecting portions between the respective ends of the two portions, said cam being rotatable about its center to locate said cam surface in difierent positions of adjustment with respect to the frame.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,162,233 Goddu Nov. 30, 1915 2,145,729 Marchev Jan. 31, 1939 2,164,549 Stephenson July 4, 1939 2,268,045 Marchev Dec. 30, 1941 

